Plastic closures, which comprise a lower part and a cover connected thereto in a swiveling manner by means of a hinge, have to be secured in such a way that the consumer recognizes whether the closure may have already been opened before the purchase and whether there is therefore the risk of the contents already having been partially removed or, something which unfortunately also occurs, having been contaminated.
Accordingly, plastic closures having integrity guarantee elements have already been on the market for very many years. The best known form of an integrity guarantee element is the guarantee band, which originally primarily produced a connection between the plastic closure and the container on which the plastic closure is fitted. Such a guarantee band is of course sufficient in the case of a screw connection. Such a guarantee band can also be used in the case of plastic closures with a hinge or a snap-on hinge with which the lower part can be fixedly connected to the container neck, wherein such a guarantee band is usually not completely circumferential, but runs around more than 180° of the circumference. The guarantee band then comprises locking hooks usually on the inner side, i.e. on the side that is directed towards the lower part in the closed state, said locking hooks engaging in the corresponding recesses in the lower part. Before such a closure can be opened, the guarantee band must therefore first to be torn off.
For reasons of user convenience, integrity guarantee elements were then developed which, when the hinge connection is first opened, automatically bring about a separation of the integrity guarantee element from the part to which this integrity guarantee element is connected by predetermined breaking points. Such a plastic closure is shown for example in WO94/03371. Here, a platelet is held by predetermined breaking point bridges in the cover in its cover surface flush with said cover surface, and molded on the underside of said platelet is an arm with a terminal locking hook, which interconnects with a counter-locking hook of the lower part. During the first opening, the platelet of the integrity guarantee element is duly torn out of the cover surface of the cover and then falls down onto the cover surface of the lower part. A clearly visible integrity guarantee thus results. In addition, such a solution has the advantage that, after the first opening, tampering with the integrity guarantee element more or less to recreate the integrity state is virtually impossible.
WO00/41943 shows a solution for an integrity guarantee element that is also difficult to tamper with. Here, the integrity guarantee element comprises a completely separate guarantee band, which engages over protruding beads on the cover and the lower part. Such a solution has the advantage that the guarantee band can be constituted in a different color from the plastic closure itself, and thus can be readily recognized visually. Here, as in the solutions for integrity guarantee elements in common use nowadays, the separated parts are relatively large and, precisely in the case of beverages which are provided with a plastic closure with a drinking spout, these integrity guarantee elements are torn off and thrown away carelessly.
A solution, wherein the integrity guarantee element is not a separate loose part, is shown for example in GB-A-2269583. Here, the plastic closure is provided with a shield-shaped tilting plate which hooks on the lower part in a swiveling manner. This shield-shaped plate is pressed for the purpose of opening and a predetermined breaking point bridge is thereby destroyed. The closure can now be opened. The problem with this solution, however, is that the consumer can scarcely recognize the integrity of the product.
Finally, a plastic closure is known from WO98/57864, according to the preamble of patent claim 1. This plastic closure comprises an integrity guarantee element which is molded on the jacket wall of the cover and which is intended to engage in a recess in the jacket wall of the lower part. The integrity guarantee element swivels here about the predetermined breaking points and comprises two lugs, which are intended to engage in corresponding holes in the jacket wall of the lower part. In addition, a tilting rib is formed in the recess in the lower part and the user is intended to press on the integrity guarantee element, wherein the tilting motion is intended to take place via the tilting rib, and the integrity guarantee element is thereby separated from the cover. The closure can now be swiveled upwards. This closure is problematic, inasmuch as on the one hand the user does not recognize the function and basically attempts to lift the integrity guarantee element. Furthermore, a swiveling motion about an arc-shaped hinge is extremely problematic and finally it has been shown that such a closure can be handled only with extreme difficulty on conventional assembly machines, and that a significant percentage of the closures are destroyed. On the other hand, the idea that the integrity guarantee element remains on the closure and is not therefore thrown away carelessly is in itself sensible.